1. Field
The disclosure relates to a method, system, and article of manufacture for position invariant compression of files within a multi-level compression scheme.
2. Background
Data compression is the process of generating compressed data from originally provided data, where the compressed data is represented in fewer bits than the originally provided data. Data uncompression is the process of generating the originally provided data from the compressed data. Data compressions may be performed via compression applications, and data uncompressions may be performed by uncompression applications. The originally provided data may also be referred to as uncompressed data.
Compression of data may be lossless or lossy. Lossless compression may exploit statistical redundancy in the originally provided data. In certain lossless compression mechanism the statistical redundancy may be eliminated or reduced to represent the originally provided data more concisely without any loss of fidelity in the compressed data. Lossy compression is possible if some loss of fidelity in the compressed data is acceptable. Lempel-Ziv (LZ) compression is an example of a lossless compression mechanism, and JPEG compression is an example of a lossy compression mechanism. Data compression has significant value in increasing transfer speeds of the data, and for increasing storage density, i.e., storing the same amount of data in a reduced amount of storage.
File aggregation is a process in which a plurality of files that are to be sent in a single transaction are stored together in an aggregated file. The individual files of the aggregated file may be accessed separately. File aggregation may improve performance by transmitting the aggregated file that includes the plurality of files in a single transaction, instead of transmitting each of the plurality of files one after the other via a plurality of transmissions. File aggregation may be useful for tape storage as it may facilitate the streaming of data to tapes without stopping to write filemarks.